Water curtain projecting device for use with sand blasting apparatus



July 7, 1953 HOGUET 2,644,275

WATER CURTAIN PROJECTING DEVICE FOR USE WITH SAND BLASTING APPARATUS Filed April 7, 1950 2 Sheets-Sheet 1 wt vimm 4 TTo Rum,

July 7, 1953 J. HOGUET 2,644,275

WATER CURTAIN PROJECTING DEVICE FOR USE WITH SAND BLASTING APPARATUS Filed April 7, 1950 2 Sheefls-Sheet 2 ATToRA/EY Patented July 7, 1953 I Y -JW-ATER :11am VPROJEGTING Device Fen I f 1. use WITH;SANDBLASTINGAPPARATUS1" it France, assignor to Societe I E. C. T. A."(So ete dEntreprise'deConstruction et de Travaux dArt) poration of Ffance' t is well known'thats anid blasting app atus According tdtheipresieht invention, this i convenience is avoided by arranging, round the end of the sand blasting tool, adevice, suitable for projecting, round the jet of sand, althin' conical screen or curtain of water under pressure,

surrounding the jet of sand'and forming, with the surface upon which this jet is projected, an enclosure'which the sand particles cannot traverse without being wetted, This" wetting augments their density and consequently causes them to fall down, so that they cannot pass into the ambient air.

Particularly effectual, results will be obtained by sending air under pressure into'the water screen, whereby the jet of sand will be surrounded with a thin conical curtain constitutedby a mixture of water and air. U

. The implementation of said water screen is subject to various difiiculties. In'particular," the amount of water to wet the sand particles must be sufficiently small to avoid thickening. On the other hand, means for carryingout this screen must be simple but solid in construction'and light in weight, and permit easy 'butaccurate regulation of the water screen'orv of the waterand-air-mixture screen, and further mustbe easily separable from the sand blasting tool in order to be, on'one hand, readily replaceablein the case of an accident in the course of ope ation, and on the other hand, ree'employable on the apparatus successive nozzles, on account oi the latter being subjectto rapid wear andtea' r. In order that the invention may j be more clearly understood, a form 1 of water andair screen projecting device embodying the same will now be described with reference to the accompanying drawings in which Fig. l is an axial section of the entire device; Fig. 2 is an axial section of'thebase component thereof; I

Fig. 3 is a plan' View corresponding to Fig.2, Fig. 4 is an axial section of the conic frustumshaped concave part of the end'comp'onentfof the device shown in Fig. 1, Fig. 51s a plan view corresponding toFig. 4;

Fig. 6 is an axial section of the firstannular r disk of the end component of the device;.-and

Fig. 7 is an axial section of the'second annu-* lar disk of the end componentof the-device;-

Similar numerals refer to similar "parts throughout the severalviews:

Q-Pa'ri's, France; a cor-" 1 T e de ic i bri e fb sey m en I, an end component zjf ormedfwitha conic frustumsha ediw avesu f i sec red .1 1 base componentflf bymeans of a threaded connection withint position of gaskets tj 5 and 'fi a first annular'diskfl secured' to the end component 2 by means of a threaded'connection 8,: with interpcsitiongof spa-cinggaskets Sand [0, and a secendani ar H se ur t the di v 1 by means of a threaded' connection 12', with interposition of a spacing "gasket I3.

' The'b'as'ecomponent l, (Figs.j2 and 3) is constituted "by a" body generated by "revolution and provided with an; axial fbore 141mmakje passage for-thesa'nd blasting-took: This component I is secured to the tool by means ofa screw l5 screwed into the neck 15 of the component I and having itspoint protruding'into' the bore I 4 The upper face ll of the component I has two concentrio annular grooveslll and I9 separated from each other by' an annular protrusion 20. The

outer groove is is connected, through the passage2l; wane fitting 22 adapted to receive a convenient conduit (not shown) forsupplying the device'with air under pressure. The inner groove lil'i s similarly connected, through a passage 23, with a fitting 24' adapted to receive a convenient conduit for supplying the devicewith water under pressure. Thecomponent I further hasa threaded portion denoted' by numeral 3. The'end component 2 (Figs. l'and 5) comprises an annulus-like member-25 formed, on one hand, 'with'a-n inwardly extended sleeve 26 internally threaded as at 3' and, on'the other hand,

with an outwardly (extended top member 2'! internally hollowed out to "a conic frustumshaped surface 28 whose angle at the apex is substantially equal to'80 j that is, to the opening of the conical water scre'enintended to be obtained. The-outermost edge ofthe topmember 2'! is preventedby reinforcementzil'from getting too The annulus-like member 25 is provided, on

one handgwith anumber of'holes as, eight for to the component! by screwing the sleeve 26 onto the corresponding threaded portion of the component I. A gasket 5, placed into the groove 32, is jammed in by the annular protrusion and forms tight seal between the grooves l8 and I9. Gaskets and 6, placed respectively between the annulus and the upper face of component I, between the groove I9 and the bore l4, and between the groove I 8 and the threads 3, render" tight the passages formed by these two grooves after the component 2 has been screwed onto the base component I The first annular disk i (Fig. 6 has a coaxial collar 32 threaded internally to form the threaded connection :2 and externally to form the threaded connection 8, and further has its edge portion thinned as shown at 33. The radial distanceof this thinned portion is substantially equal to that of the groove 18, and the disk edge is consti tuted by a conic frustum-shaped surface 34 whose angle at the apex is substantially equal to 80, the radii of the surface 35 being such that this edge may be brought in contact with the surface 28 when the disk I is screwed down into the component 2 without interposition of gaskets. Moreover, the non-thinned portion of the disk '5 is provided with holes 35, for example eight in number, disposed at a distance from the disk center equal to that separating the holes SE from the center of annulus 25 coaxial with the disk i. The latter is made rigid with the component 2 by means of the threaded connection 8. Two gaskets 9 and it], placed sidewise of the hole 35, assure the tightness between the said holes and the chamber formed by the thinned portion 33,- annulus 25 and wall 28, and permit of adjusting by positioning the disk 'i,.the thickness of the thin conical passageway existing between the surfaces 28 and 34. V

The second annular disk H (Fig. '7) likewise has a coaxial collar 36 externally threaded to form the threaded connection i2. The inner radius of this disk as well as that of the collar 36, are equal to the radius of the bore 14 made through the base component i. The disk H has a thinned edge portion 3? and the inner radial distance or" this thinned portion is substantially equal to that of the groove iii of base component I. The outer edge of this disk is constituted by a conic frustum-shaped surface 33 whose angle at the apex is substantially equal to 80, the radii of said surface being substantially suchthat this edge may be brought in contact with the surface 26 when the disk H is screwed down,

without interposition of gaskets, into the disk- I placed in the device. The disk H is made rigid with the disk '5 by means of the threaded connection 2. A gasket I3 placed between the disks '1 and H, against the non-thinned portions thereof, permits of adjusting, by positioning the disk 5 I, the thickness of the thin conical passageway existing between the surfaces 28 and S8.

The device, thus constituted, is mounted on the fitting 24, flows through the passage 23 into the annular groove I9, from which it flows through the passageways 3l35 into the annular chamber formed by the thinned portion 31 of disk H, and is finally drawn from this chamber by the thin layer of air escaping between the walls 28 and 38, and being mixed therewith.

In this way there is obtained a thin conical screenor curtain produced by a mixture of water and air, positively stopping sand dusts. The thickness of this curtain, as well as the relative proportions of water and air, are adjusted by varying, on one hand, the thickness of the gaskets 9, NJ and, on the" other hand, the thickness of the gasket l3. 7

The device, thus designed and constructed, may be rapidly and easily separated from the sand blasting tool, when it is necessary either to change the tool nozzle,--or to change the device itself on account of its failure, which latter, however, is practically excluded.

Obviously, modifications of detail may be effected in the particular constructions, described and shown, without substantially departing from the invention itself which is intended to be defined in the appended claims.

What is claimed is:

l. A device for preventing the dispersion, iii

the atmosphere, of siliceous particles arising from sand blast apparatus, which includes, an annular base component provided with an axial bore for the purpose of removably securing this component onto the sand blasting tool passing through this bore, a coaxial annular end component securable onto said base component and provided with an internal conic frustum-shaped surface having its large base opened outwardly, toward the periphery of the spot to be sandblasted by the said tool, and its small base formed toan annulus coaxial with said components and bore, a first annular core member coaxial with and adjustably securable, within said conic frustuin-shaped surface, to said annulus and adapted to form with this surface a first thin annular passage directed toward the periphery of the said spot, a second annular core member coaxially disposed over and adjustably securable, within said surface, to said first core member and adapted to form with this surface a second thin annular passage disposed over said first thin passage and also directed toward the periphery of the spot, air canalizing passages .managed in said base component and said annulus for feeding air under pressure into and through said thin annular passages, and water canalizing passages managed in said base coinponent, as well as in said annulus and first annular core member, for feeding water under pressure into a chamber between said annular core members and through the said second thin annular passage to be mixed therein with said air, so as to thereby permit of projecting a thin conical water-andeair screen or curtain under pressure encompassing the 'jet of sand produced by the said tool, all substantially as set forth.

2. Device as defined in claim 1 wherein said first annular core member is an annular disk peripherally thinned to form a variable chamber communicating, through hole-s provided in the said-annulus, with the air canalizing passages, while second annular core member is an annular disk peripherally thinned to form a variable chamber communicating, through holes provided in the first named annular disk and in the said annulus, with the water canalizing passages-the said two grooves being insulated from each other v by means of an intermediate annular gasket concentric with these grooves, and further comprise two conduits, managed in the body of the base component, one being adapted to feed compressed air into the air distributing groove and the other to feed water under pressure into the water distributing groove, all substantially as described.

4. Device as defined in claim 1 wherein the said components, as well as the said annulus and annular disks, are secured to one another by means of threaded connections and tightly insulated from one another by means of suitably interposed annular gaskets substantially as described.

5. A device for preventing the dispersion of fine dry particles away from the working end of a tool, which comprises a spray unit securable to the end of the tool providing a relatively thin, annular frusto-conical passage diverging outwardly in the direction of the discharge end of said tool, means defining a thin, annular passage communicating with said frusto-conical passage inwardly of the discharge end of said tool, means for supplying water to said second-named passage to provide a thin layer of water lying in a plane substantially at right angles to the axis of said tool and means for supplying air under positive pressure to said first-named passage, whereby to provide a thin, annular curtain of air moving past said second passage to project a thin, annular curtain of air containing particles of water suspended therein diverging outwardly from the discharge end of said tool.

6. A device for preventing the dispersion of fine dry particles away from the working end of a tool duct adapted to project a jet of said fine particles suspended in air under pressure, which comprises a spray unit securable to the end of the tool duct providing a relatively thin, annular frusto-conical passage diverging outwardly in the 6 direction of the discharge end of said tool duct, means defining a thin, annular passage communicating with said frusto-conical passage inwardly of thedischarge end of said tool duct, means for supplying water to said second-named passage to provide a thin layer of water lying in a plane substantially at right angles to the axis of said tool and means for supplying air under positive pressure to said first-named passage, whereby to provide a thin, annular curtain of air moving past said second passage to project a thin, annularcurtain of air containing particles of water suspended therein diverging outwardly from the discharge end of said tool duct and surrounding the jet of fine dry particles issuing therefrom without intermixing therewith.

'7. 'A device for preventing the dispersion of fine dry particles away from the working end of a tool duct adapted to project a jet of said fine particles suspended in air under pressure, which comprises a spray unit securable to the end of the tool, said unit having an internal frusto-conical surface diverging outwardly in the direction of the dis charge end of said tool duct, core means adjustably securable in said unit to define with said surface a frusto-conical annular passage of variable thickness, a relatively thin annular frusto-conical passage diverging outwardly in the direction of the discharge end of said tool duct, means defining a thin, annular passage communicating with said frusto-conical passage inwardly of the discharge end of said tool duct, means for sunplying water to said. second-named passage to provide a thin layer of water lying in a plane substantially at right angles to the axis of said tool and means for supplying air under positive pressure to said first-named passage, whereby to provide a thin, annular curtain of air moving past said second passage to project a thin, annular curtain of air containing particles of water suspended therein diverging outwardly from the discharge end of said tool duct and surrounding the jet of fine dry particles issuing therefrom without intermixing therewith.

JU'LES I-IOGUET.

References Cited in the file of this patent UNITED'STATES PATENTS Number Name Date 2,324,250 Voerge July 13, 1943 2,376,287 Sorrentino May 15, 1945 2,440,334 Gerlach Apr. 27, 1948 

